I am working on a problem that part of the solution of file A is the condition for file B. My intention is to run file A and unload the part of solution needed by file B. After that, file B will load the solution from file A. Regarding my intention, my code is as following:

When I run the file A, everything looks fine. However, there are errors when I run file B: cannot load/unload symbols with unknown dimension. Can anyone help me? Thank you very much. Besides, is there any way that I can execute an external file in GAMS? Thanks again.